a = [0 for i in range(10)]
sa = {0 for i in range(10)}
b = [1, 2, 3]
bb = [i * 10 for i in b]
sb = {1, 2, 3}
sbb = {i * 10 for i in sb}
c = ["www", "immoc", "com"]
cc = [i.upper() for i in c]
dc = {i: i.upper() for i in c}
sc = {"www", "imooc", "com"}
scc = {i.upper() for i in sc}
d = [1, 2, 3, -1, -2, -3]
dd = [i for i in d if i > 0]
sd = {1, 2, 3, -1, -2, -3}
sdd = {i for i in sd if i > 0}
matrix1 = [[0 for col in range(2)] for row in range(3)]
matrix2 = [[1, 2, 3], [4, 5, 6]]
matrix = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12], [13, 14, 15, 16]]
matrix3 = [matrix[row][col] for row in range(2) for col in range(3)]
se = {x + y for x in "ABC" for y in "XYZ"}
de = {"TOM": 95, "JERRY": 80, "MIKE": 99, "JOHN": 70}
good = {name: grade for name, grade in de.items() if grade > 90}
